media: ti-vpe: cal: add camerarx enable/disable refcounting

The following patches add multistream support and we will have multiple
video devices using the same camerarx instances. Thus we need
enable/disable refcounting for the camerarx.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>